With a quartz crystal microbalance (QCM) we have studied the nanofriction of neon and other simple gases deposited on lead at low temperature. Special care has been paid to the investigation of some artifacts in the QCM response encountered after the initial cooldown. Extensive results obtained with QCMs that have been thermally annealed confirm that Ne films slide on Pb below 10 K. However, no extra dissipation is observed when the Pb electrode is driven either magnetically or thermally into the metallic state. This means that the electronic contribution to friction is negligible for this system, probably, because of the small polarizability of Ne atoms. More polarizable adsorbates like N 2, Kr, and Xe are instead found to be completely pinned to Pb below 10 K.
American Physical Society
28 Jul 2011
Volume: 84 Issue: 3 Pages: 035448
Physical Review B